Centrifugation draught fan volute

Abstract

Disclosed is a centrifugation draught fan volute. A volute molded line of the centrifugation draught fan volute includes a starting line AC located on one end of the molded line, and a finishing lineMN located on the other end of the molded line. The volute molded line between the starting line AC and the finishing line MN is a spiral line. The centrifugation draught fan volute is characterized in that the spiral line includes a first spiral line CD connected with the starting line AC and a second spiral line DM connected with the finishing line MN. The first spiral line CD is an equiangularspiral line. The second spiral line DM is a variable angle spiral line with a divergence angle contracting gradually. The centrifugation draught fan volute has the advantages that according to the centrifugation draught fan volute, through arranging the first spiral line CD between the starting line AC and the finishing line MN into the equiangular spiral line, and arranging the second spiral lineDM into the variable angle spiral line with the divergence angle contracting gradually, the left-and-right size of the volute is shrunk, the fluency of the volute internal airflow collection and flowing through is improved; the maximum static pressure and the static pressure of an effective air volume section are obviously improved; a large volute effect in small size is achieved, and meanwhile,the aerodynamic noise is reduced, and the user experience is improved.

Description

technical field [0001] The invention relates to a fan, in particular to a centrifugal fan volute. Background technique [0002] Centrifugal fans have been widely used in range hoods for their advantages of high suction, low noise, and compact structure. The volute is one of the core components of the centrifugal fan. Its function is to concentrate the gas leaving the impeller, export it to the outlet of the volute, and convert the dynamic pressure into static pressure. The volute structure of the existing centrifugal fan includes a volute top plate, a volute bottom plate, and a volute coaming plate connecting the volute top plate and the volute bottom plate, wherein the volute top plate and the volute bottom plate have the same profile except for the volute tongue. The traditional volute design is generally carried out according to the unary theory, and there are two assumptions, that is, assuming that the flow parameters on the inlet circumference are uniformly distributed...

AI Technical Summary

Problems solved by technology

But in fact, due to the non-axisymmetric shape of the volute, especially the influence of the volute tongue, a non-uniform pressure field will be formed at the outlet of the impeller, which will inevitably make the flow field at the outlet of the impeller, that is, the flow field at the inlet of the volute.

Since the one-element theory does not consider the non-uniformity of the inlet circumferential flow parameters and the influence of the flow field in the circumferential plane of the volute, the performance of the volute designed according to this theory is not good, especially in the high back pressure working state. , In addition, the left and right dimensions of this volute are generally relatively large, which affects the product's overall size

[0003] The volute structures of various centrifugal fans are also disclosed in the prior art, such as "A Centrifugal Fan for Range Hood and Its Volute" as disclosed in the Chinese invention patent No. ZL 201110118687.5 (authorized announcement No. CN 102182707 B). Shell profile line generation method", the volute includes a volute top plate, a volute bottom plate and a volute coaming, the contour line of the inner side of the volute coaming is the volute profile, and the volute profile is formed by the first straight line DE , the first arc line EF, the second arc line FG, the helix line GH, and the second straight line segment HI are smoothly transitioned and connected. Although the volute adopts the above-mentioned volute profile, it is beneficial to improve the air volume and air volume of the centrifugal fan. pressure, efficiency and reduce aerodynamic noise, but the structure of the volute still does not fully consider the non-uniformity of the inlet circumferential flow parameters and the influence of the flow field in the circumferential plane of the volute, and further improvement is needed

Images